Atomic Transit and Delayed Ionization Effects on Cesium Beam Frequency Standards
Abstract
In a compact cesium beam atomic clock, the magnets that perform state selection and analysis transmit a narrow slice of the Maxwellian velocity distribution leaving the cesium oven. Increasing the width of the transmitted velocity distribution will increase the beam intensity, and thus the clock's signal-to-noise ration, but it will also distort the atomic beam amplitude modulation, which gives the clock error signal, and thus reduce the signal-to-noise ratio. Detection is accomplished by surface ionization on a hot wire, which acts as a low-pass filter. The combined effects of these processes on the clock's error signal are analyzed in detail for a test case involving an atomic beam which has been square-wave amplitude-modulated by its interaction with the frequency-modulated microwave field. While our analysis has been performed for the type of compact cesium beam tube used on board Global Positioning Systems satellites, its most general conclusions are valid for any atomic beam passive-frequency standard and show the importance of processes taking place after the atom-microwave interaction is completed for the optimization of the clock's performance. Keywords: Atomic Clock; Cesium Beam Frequency Standard; Atomic Beam Modulation.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 12, 1988
- Accession Number
- ADA196216
Entities
People
- Bernardo Jaduszliwer
Organizations
- The Aerospace Corporation